Shuttleless loom weft control device

ABSTRACT

A shuttleless loom weft control device comprises, for each weft, a rocking lever whose position is determined by the advance of the weft during its insertion, having a thread tightener at one end for this purpose. At the other end of the lever is a permanent magnet facing which are situated, for the two extreme positions of the lever, magnetic blade switches connected respectively to two working and resting contacts of a weft thread selector. The lever cooperates with a switch whose successive openings and closings are synchronized with the motion of the loom. The movement of the lever is cam- or electromagnetgoverned so that the lever is free to rock during the second part of the thread drawing. The loom-synchronizing switch comprises a magnetic rotating pastille or a cam coordinated with the lever cam. The weft thread selector has a thread selector element for each weft thread and each has a permanent magnet which closes one or other of the working and resting contacts.

United States Patent [72] lnventor Michel Gabet Montigny en Cambraisis,France [21] Appl. No. 739,697 [22] Filed June 25, 1968 {45] PatentedJan. 12,1971 [73] Assignee Fatex Lyon (Rhone), France [32] Priority June30, 1967 [33] France I [31] No. 112,685

[54] SHUTTLELESS LOOM WEFT CONTROL DEVICE 10 Claims, 14 Drawing Figs.

[52] US. Cl 139/122, 139/370: 66/163 [51] Int. Cl D03d 47/34. 1 D03d51/34 [50] Field of Search 139/122, 370; 66/157, 158, 163

[56] References Cited UNITED STATES PATENTS 3,092,150 6/1963 Brimans etal. 139/370 3,272,239 9/1966 Ancetetal.

ABSTRACT: A shuttleless loom weft control device comprises, for eachweft, a rocking lever whose position is determined by the advance of theweft during its insertion, having a thread tightener at one end for thispurpose. At the other end of the lever is a permanent magnet facingwhich are situated, for the two extreme positions of the lever, magneticblade switches connected respectively to two working and restingcontacts of a weft thread selector. The lever cooperates with a switchwhose successive openings and closings are synchronized with the motionof the loom. The movement of the lever is camor electromagnetgoverned sothat the lever is free to rock during the second part of the threaddrawing. The loom-synchronizing switch comprises a magnetic rotatingpastille or a cam coordinated with the lever cam. The weft threadselector has a thread selector element for each weft thread and each hasa permanent magnet which closes one or other of the working and restingcontacts.

PATENTED'JAN 12197:

sum D3UF12 PATENIED JAN 1 2 1971 SHEET Uh HF 12 PATENTEDJANIZIHII3.554.239

sum new-12 PATENTEU Arnzlsn 3554239 sum 07 0F 12 PATENTEU A 1 21 1' 3;554} 239 SHEET us [1F 12 PATENTEDJANIZIQW 35 4. 239

SHEET 12 0F 12 present invention is characterized in that it comprises,for

each weft thread, a rocking lever the position of which is determined bythe advance of the correspondingweft thread at the moment of itsinsertion, one of the ends of this lever comprising for this purpose athread tightener and atits other end, a permanent magnetfacing which aresituated, for the two extreme positions of said lever, two magneticblade switches connected to contacts, working and resting, of a weftthread selector cooperating, with a switch the successive openings andclosings of which are in synchronism with the movement of the loom. i

In one embodiment according to the invention, the control of eachrocking lever is ensured by a cam of which the circular profile of onepart of its circumference thereby ensures its liberation in the secondpart of the drawing of the thread, so that, in this second part, thislever is free to rock if it is drawn by its thread, the boss of this cambringing .the said-lever back into its initial control position for thefollowing cycle when the switch functioning in synchronism with themotion of the loom, is again open.

In another embodiment according to the invention, the switch whosesuccessive openings and closings are in synchronism with the motion ofthe loom, is controlled by a FIG. 1 shows in section in side elevationan embodiment of a welt control device according to the invention havingmechanical control by a cam and in the position corresponding to thesecond part of entrainment of the weft, which corresponds'also to theposition in the case of an undesirable thread;

FIG. 2 is a view similar to the preceding one but in the position of thelever during the first part 'of the drawing of the weft,

which position corresponds alsoto that produced in thelcase of thebroken weft;

FIG. 3 is a viewin elevation-of an assembly equipped .for a loomoperating with multiple wefts;

FIGS. 4 and 5 are views respectively analogous to those of FIGS. 1 and2, but in plan view from aboveof another'embodiment of a weft controldevice according to the invention having electromagnetic control;

FIG. 6 is a, sectional side view in elevation of the embodiment of-FIG.5;

FIG. 7, 9, 11 and 13 are diagrammatic illustrations showing the generaloperation of the electromagnetic embodiment. respectively in the foursituations which can occur; and

FIGS. 8, 10, 12 and Marc views respectively similar to the fourpreceding ones for the mechanical embodiment employing cams.

In the mechanical embodiment of FIGS. 1 to 3, in a housing 1 aremounted,'for free rocking around a horizontal shaft 2 as many levers 3as the loom comprises weft threads 4 to be controlled and to be insertedselectively in the cloth. The positionmagnetic contact influenced by amagnetic pastille, turning in- I tegrally with the cam.

Thus, when one of the levers ing the thread and while the latter is notbroken, the permanent magnet of the said levercloses the circuit of oneof the two magnetic switches connected to the resting contacts of theselector and the magnetic pastille turning integrally with-the controlcam of the corresponding lever comes to face its contact and closes it,but as the first switch' is not influenced by the magnet of the lever,this switch remains open and the electric current of the driving motorof the loom is not cut.

On the other hand, if the tread is broken, the lever does not rock atthe end of the course of the pick and the first magnetic switch remainsclosed so that at thev rnoment when the magnetic pastille comes to faceits contact, the latter cuts the current.

The same happens in the case where an undesirable neighboring thread isdrawn in error with the thread, relating to a weft. In fact, in thiscase, the corresponding lever rocks and the first magnetic switch isopened but the second is closed, and, as it is in circuit by theerroneous entrainment of the thread, the 'contact, ensured by theturning magnetic pastille, stops the driving motor of the loom.

As a variation, .each rocking lever is-de'pendent on an electromagnetwhich is not fed in the second part of the drawing of the thread, sothat, in this second part, this lever is free to rock if it is drawn byits thread, the electromagnet being 'again fed after the end of thedrawingof the-weft tobring this lever-back into its initial controlposition for the following cycle, as soon as the switch functioning insynchronism 'with the movement of the loom is again open.

Also as another-variation, the switch whose openings and closing are insynchronismwith the motion of theloom, is constituted by two blades oneof which is positivelycontrolled by a cam.

The operation of this latter control system by an electromagnet,--isidentical with that previously described for the mechanical controlsystem by a cam.

In order that the invention may be'more fully understood there are nowdescribed in more detail the aforesaid 'various embodiments purely byway of nonlimiting' example with reference to the accompanying drawingsin which:

rocksin the direction of drawing of these levers axially on their shaft2 is ensured by means of stop rings 5 (FIG. 3).

Each of these levers 3 bears at its upper part a thread tensionerconstituted, in knownmanner, by a set of cups 6 urged into contact withone another, by a spring 7 of adjustable tension, and between whichslips the thread which, upstream and downstream of this tensioner,passes under guides 8.

i Each of the levers 3 is'equipped with a follower 9 which slides over acam 10 and the assembly of all these cams is fixed on a shaft 12 therotation of which is controlled, in synchronism with the motion of theloom, by a bevel gear '13 from a cardan transmission 14.

At its lower end, each of the aforesaid levers 23 is provided with amagnet 15 coming into position for the two end posipassing, during itsrotation, in front of a magnetic-contact 20 inserted in the circuit oftheaforesaid magnetic blade switches 16 and 17. The operation of thecams 1-0 is such that during the first part of the drawing of the thread4, the bosses of.- the .cams.l0 action. againstfollowers 9 to rockthe-leversto the position shown in FIG. 2, the switches-16 beingtherefore closed by reason of the presence of the permanentmagnets 15which are positioned opposite themagnetic switchesl'6; on

- the other hand, in the last partof the drawing of .the thread-,4, theboss of the cams 10 is withdrawn from the followenas shown in FIG. 1which permits the levers to rockunder theactionwhich they canreceivefrom their thread during the-drawing of the latter and its slippingbetweentthe cups,6, in which case the magnetic switch 17 is closed.

In the magnetic embodiment, of FIGS. 4 to 6, the same members are usedwith. the difference, however, that. the levers 3 are located in ahorizontal plane, and the ,shaft 2 around which they .rock, is vertical.Moreover, thecontrolof these levers is not ensured mechanically by acam, but, for each lever there is an electromagnet 22 which is only fedwith current during the first part of the drawing of the thread4.

On the other hand, each lever 3 comprises a small ,angle bracket 23which is selectively displaced by ahinged flap,2 4.of its respectiveelectromagnet 22 as best seen in FIGS..4,' Sand 7. The flap 24 issubjected to the action of a spring-25 urging the flap to an extendedposition as shown in FIGS. 4 and 7. The electromagnet when energized,pivots the flap 24 inwardly against the opposite of spring 25 and theflap engages angle bracket 23 to pivot the same about shaft 2 as shownin FIG. 5. The magnetic switch 19, 20 of FIGS. 1 to 3 is replaced by amechanical switch controlled in synchronism with the motion of the loom.This switch is constituted by two blade contacts 26 of which one isactuated mechanically by a cam 27 (FIG. 7)

As regards this electromagnetic arrangement of FIGS. 4 to 6, each of theelectromagnets 22 is only energized as indicated hereinbefore, duringthe first part of the drawing of the thread 4. In the first part of thedrawing of the thread, the flap 24 of the electromagnets 22 is retractedand the angle bracket 23 is fixed on the corresponding lever 3 iscorrespondingly retreated as shown in FIG. 5. The magnet of these leversis then opposite the magnetic blade switch 16 and thereby ensures itsclosing. On the other hand in the last part of the drawing of thethread, a cam 31 opens a switch 30 and electromagnets 22 are no longerenergized. The flaps 24 are urged by their springs 25 away from brackets23 and therefore free the levers 3 enabling the latter to rock under theaction which they can receive from the thread during the drawing of thelatter and of its sliding between the cups 6 in which case, the magneticblade switch 17 is closed.

For the case of the electromagnetic embodiment (FIGS. 7, 9, 11, 13) theenergization of electromagnets 22 is obtained from the output of analternating current transformer 29. This supply is controlled, asindicated above, by a switch 30 controlled by a cam 31, turning insynchronism with the movement of the loom.

In the circuit is inserted a rectifier 32 which has the simple functionof enabling the use for the electromagnets 22, of reels of smalldimension and to reduce the wear of the flaps 24 by suppressingvibrations.

Finally whether it relates to one or other of the aforesaid arrangements(FIGS. 1, 2, 3, 8, 10, 12, 14) or (4, 5, 6, 7, 9, 11, 13), the apparatuscomprises, besides the properly so-called weft stop motion shownsymbolically at 34, a selector 35 comprising as many thread selectorelements (screw plates) 36 as threads 4 to be controlled, each selectorelements being equipped with a permanent magnet 37 positioned, accordingas the selector element is lowered or raised by its control lever 38 infront of a magnetic switches 39 and 40. The closing of the circuit tothe ground 41 is established by a common point 42 situated between thesetwo latter contacts.

The general operation of this weft stop motion is the following for thefour cases which can occur, it being specified that all the explanationsrelated here, concern the position of the assembly of members in thelast part of the drawing of the thread of the weft which arrives at thecontroller 34 under a slight tension resulting from the action of anybraking system (not shown).

1. Case of normal advancing of the weft thread desired being stillsuitably drawn and not being broken (FIGS. 7 and In the case of theelectromagnet embodiment (FIG. 7) the electromagnet 22 is no longerenergized, the cam 31 having opened the switch 30. The pressure exertedby the cups 6 on the thread 4 (which is displaced in the direction ofthe arrow) causes the lever 3 to be rocked so that its magnet 15 isfacing the magnetic switch 17 to close the same while the magneticswitch 16 is open. On the other hand, the selector element 36 beinglowered, its magnet 37 is opposite-switch 39 and closes it, The switch40 being open. On the other hand, the cam 27 having closed switch 26,the current which arrives at the common point 43 passes by the magneticswitch 17 and is directed to the selector 35 where it arrives at thecontact 40 which, being open, prevents its passage. There is, therefore,no signal and the loom continues to operate.

In the case of the mechanical embodiment (FIG. 8) the operation is thesame, the magnet 15 having closed the magnetic switch 17 and themagnetic pastille 19 having closed the switch 20.

2. Case where the weft thread is held waiting without being either drawnor broken (FIGS. 9 and 10) In the case of the electromagnet embodiment(FIG. 9) the lever 3 which has been previously retracted by theelectromagnet 22 and which is freed in the second part of the drawing ofthe thread, due to the deenergization of this electromagnet, the lever 3is freed but it remains in place since it is not drawn by the thread.The magnet 15 remains therefore opposite the magnetic switch 16 andcloses it. From the common point 43 the current passes by this switch 16and arrives at the switch 39 of the selector, but the selector element36 is not lowered. Its magnet 37 is not therefore opposite the switch 39so that the latter is open and does not permit the passage of current.As in the preceding case l there is no signal and the loom continues tooperate, the weft thread being held waiting,

not having been selected.

In the case of the mechanical embodiment (FIG. 10) the operation is thesame. In fact, the lever 3 having remained in place, the magnetic switch16 is closed by the magnet 15 and the switch 20 is itself closed by themagnetic pastille 19.

3. Case in which the weft thread which has been selected has broken andthus is no longer drawn (FIGS. 11 and 12) In the case of theelectromagnetic embodiment (FIG. 11) the lever 3 which has beenretracted by the electromagnet 22 in the first part of thread drawing,is freed since electromagnet 22 is not supplied, the opening of thiscircuit having been obtained in the second part of the drawing of thethread by the cam 31. The lever 3 is therefore free and since it is notlonger subject to the traction of the thread as the latter has broken,the lever remains immobile, its magnet 15 remaining opposite themagnetic switch 16 which it closes. From the common point 43 the currenttherefore passes this switch 16 and arrives at the switch 39 of theselector 35. This contact being closed by the presence of the magnet 37of the selector element 36 which is lowered, the current passes andarrives at the common point 42 and, from there, to the ground 41.Therefore a signal is produced and the loom is stopped.

The operation is established in the same manner in the case ofmechanical control by cam (FIG. 12). In fact, the lever 3, not havingbeen brought back by the traction of the thread, remains in the positionthat has been given to it by the boss of the cam 10 and the magnet 15 oflever 3 closes the magnetic switch 16.

4. Case of an undesirable thread (FIGS. 13 and 14) In the case of theelectromagnetic embodiment (FIG. 13) the lever 3 which has been freed bythe electromagnet 22 tilts when an undesirable thread advances since itis drawn and the permanent magnet 15 of the said lever closes themagnetic switch 17.

From the common point 43 the current passes therefore through switch 17and arrives at the selector 35 up to the input of the switch 40. Theselector element 36 not being lowered, this contact is closed by themagnet 37 and the current passes therefore to the common point 42, and,from there, to the ground 41. Therefore a signal is produced and themotor is stopped.

In the case of the mechanical embodiment (FIG. 14) the operation isestablished in the same manner, the current passing the switch 20, theswitch 17 and the switch 40 all of which are closed.

It will be apparent that various changes and modifications may be madein the embodiments hereinbefore described without departing from theessential concept of the invention as defined in scope by the appendedclaims.

Iclaim:

1. Weft selecting and detecting apparatus for shuttleless loom, saidapparatus comprising, for each weft thread, a lever supported for freepivotal movement about an axis of rotation. a tensioning device on saidlever engaging the associated weft thread, means acting on said lever todisplace the same to a first limit position, said lever being displacedto a second limit position by the tension in the thread with said meansinoperative, a permanent magnet on said lever, two magnetic bladeswitches positioned to face the permanent magnet on said lever in arespective limit position, a weft selector comprising a selector elementfor each thread weft, and switch means connected to the blade switchesand controlled by the selector element to be shifted between first andsecond states, and a further switch connected to the blade switches andperiodically opened and closed in synchronization with loom motion, saidmagnetic blade switches, switch means and further switch being connectedin circuit for indicating the existence of thread breakage or thepresence of an undesireable thread.

2. Apparatus as claimed in claim 1 wherein said means acting on saidlever comprises a rotatable cam with first and second portionssequentially in contact with the lever such that in a first part of thedrawing of the associated weft thread the lever is in the first limitposition and in a second part the lever is free to move to the secondlimit position under the tension in the thread.

3. Apparatus as claimed in claim.2 wherein said further switch comprisesa magnetic contact, and a magnetic pastille coupled to and rotating withthe cams to alternately pass in front of said contact to close theswitch.

4. Apparatus as claimed in claim 2 wherein said switch means comprisesopen and closed switches which are alternately operated and a permanentmagnet on each selector element adjacent the open and closed switchesfor controlling the states thereof in alternation. I

5. Apparatus as claimed in claim 1 wherein said means acting on saidlever comprises an electromagnet which is energized in a first part ofthe drawing of the associated weft thread to displace the lever to itsfirst limit portion and is deenergized in a second part of the drawingof the thread so that the lever is free to move to its second limitposition under the tension in thethread.

6. Apparatus as claimed in claim 5 wherein said further switch isconstituted by two blades and comprising a cam positively controllingone of said blades to open the further switch.

7. Apparatus as claimed in claim 5 wherein said switch means comprisesopen and closed switches which are alternately operated and a permanentmagnet on each selector element adjacent the open and closed switchesfor controlling the states thereof in alternation.

8. Apparatus as claimed in claim 1 wherein said further switch comprisesa fixed magnetic contact and a magnetic pastille driven with said meanswhich displaces the lever to alternately pass in front of said contactto close the switch.

9. Apparatus as claimed in claim 1 wherein said further switch isconstituted by two blades and comprising a cam positively controllingone of said blades to open the further switch.

10. Apparatus as claimed in claim 1 wherein said switch means comprisesopen and closed switches which are al ternately operated and a permanentmagnet on each selector element adjacent the open and closed switchesfor controlling the states thereof in alternation.

1. Weft selecting and detecting apparatus for shuttleless loom, said apparatus comprising, for each weft thread, a lever supported for free pivotal movement about an axis of rotation, a tensioning device on said lever engaging the associated weft thread, means acting on said lever to displace the same to a first limit position, said lever being displaced to a second limit position by the tension in the thread with said means inoperative, a permanent magnet on said lever, two magnetic blade switches positioned to face the permanent magnet on said lever in a respective limit position, a weft selector comprising a selector element for each thread weft, and switch means connected to the blade switches and controlled by the selector element to be shifted between first and second states, and a further switch connected to the blade switches and periodically opened and closed in synchronization with loom motion, said magnetic blade switches, switch means and further switch being connected in circuit for indicating the existence of thread breakage or the presence of an undesireable thread.
 2. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises a rotatable cam with first and second portions sequentially in contact with the lever such that in a first part of the drawing of the associated weft thread the lever is in the first limit position and in a second part the lever is free to move to the second limit position under the tension in the thread.
 3. Apparatus as claimed in claim 2 wherein said further switch comprises a magnetic contact, and a magnetic pastille coupled to and rotating with the cams to alternately pass in front of said contact to close the switch.
 4. Apparatus as claimed in claim 2 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.
 5. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises an electromagnet which is energized in a first part of the drawing of the associated weft thread to displace the lever to its first limit portion and is deenergized in a second part of the drawing of the tHread so that the lever is free to move to its second limit position under the tension in the thread.
 6. Apparatus as claimed in claim 5 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.
 7. Apparatus as claimed in claim 5 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.
 8. Apparatus as claimed in claim 1 wherein said further switch comprises a fixed magnetic contact and a magnetic pastille driven with said means which displaces the lever to alternately pass in front of said contact to close the switch.
 9. Apparatus as claimed in claim 1 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.
 10. Apparatus as claimed in claim 1 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation. 